American and Chinese officials are working to bring back more passenger flights between the world’s two largest economies, another sign of progress following deals struck last week between Presidents Joe Biden and Xi Jinping in California.

Civil Aviation Administration of China chief Song Zhiyong held talks with the US ambassador Nicholas Burns Tuesday in Beijing, the regulator said in a statement on Wednesday. The duo had “in-depth” discussions on significantly increasing flights and enhancing cooperation between the two countries’ civil aviation sectors across the board, the Chinese readout added.

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Burns described his meeting with Song as “productive” in a post on X, formerly known as Twitter. “Aviation connects us all, and US firms enable that connectivity in China and the world,” he added.

The Hong Kong-listed shares in China’s biggest airlines traded lower Thursday. As of 9:41 a.m. local time, China Southern Airlines Co. declined 1%, China Eastern Airlines Corp fell 0.8% and Air China Ltd. was down 0.7%. The benchmark Hang Seng Index dropped 0.7%.

Biden’s Nov. 15 talks with Xi on the sidelines of the Asia-Pacific Economic Cooperation summit had yielded progress in repairing strained ties in the bilateral relationship, hailing agreements to restore high-level military communications, combat fentanyl and open a dialogue over artificial intelligence. The meeting also saw an agreement to substantially increase flights between the two countries early next year, according to Chinese Foreign Minister Wang Yi.

Shortly after the summit, Air China Ltd. announced it will resume flights to Washington and increase its service to Los Angeles starting this month.

Flights between the US and China, which averaged 340 a week before Covid-19 sent the world into lockdowns, were slow to return after pandemic controls lifted. American officials said last month that flights between the countries would increase to 70 a week in early November.

Song also attended the US-China Aviation Cooperation Program reception held at Burns’s residence and addressed an audience of more than 100 that included officials from aviation regulators in both countries as well as representatives from Boeing Co. including its China head Alvin Liu and other firms. China is encouraging American aviation businesses to invest and expand in the country, he said.